This invention relates to implements, such as implements joined with a tractor. The invention relates especially to apparatus and methods used to join the implement to the tractor, and to manipulate the joining with respect to the tractor.
The invention as a whole is most closely related to joining of implements to a tractor having a conventional three-point hitch, including a pair of lower hitch arms, and an upper hitch arm. The lower hitch arms are typically permanently mounted to the tractor, and are powered by an hydraulic system whereby the distal ends of the lower arms are raised or lowered. The upper hitch arm is typically not powered. Its distal end is free to be raised or lowered along with the raising or lowering of the implement, which is joined to the tractor, by the lifting power transmitted through the lower hitch arms.
The three-point hitch generally utilizes three joining elements near the distal ends of the three hitch arms for joining with three corresponding joining elements on the implement, whereby the operating hitch uses 3 pairs of joined joining elements. The three joining elements on the hitch arms typically comprise holes extending through the hitch arms. When joined, the three pairs of joined elements, two lower pairs and one upper pair, define a plane, through the three loci of joinder, which plane more or less approaches a perpendicular with the ground.
Allowing for variations between equipment manufacturers, the upper pair of joined elements, at the distal end of the upper hitch arm, is generally about 8 inches to about 16 inches above a straight line connecting the two lower pairs of joined elements, and defines at least a part of the top of the implement. Accordingly, implements designed to be joined with the tractor, using a three-point hitch, conventionally employ an upper joining means element which is similarly positioned about 8 inches to about 16 inches above a straight line connecting the two lower joining means elements on the implement. Typically, the upper joining means element, and structural members connected to it, represent and define at least part of the top of the implement.
It is an object of this invention to provide an implement interface for use between the implement and the tractor wherein the interface includes structural members extending between members defining the front and rear of the interface.
It is another object to provide an implement interface having rear joining means elements, adapted to be joined with an implement, which joining means elements, as a group, are symmetric with respect to an imaginary plane having a substantially horizontal longitudinal axis extending from the front of the interface to its rear.
Yet another object of the invention is to provide an implement interface which accommodates 180 degree rotation of an implement with respect to the interface.
Still another object is to provide an implement interface adapted to accommodate 180 degree rotation at a first position of engagement between the implement and the interface, and to prevent rotation at a second position of engagement.
Another object of the invention is to provide novel implements which accommodate 180 degree free rotation of the implement about an axis extending between the implement and the vehicle.
It is another object of the invention to provide an implement which has two or more sets of working elements, which sets of working elements have different types of working surfaces for working the ground at different times, in non-concurrent steps.
Still another object is to provide an implement, for attachment to a vehicle having a three-point hitch, through an implement interface, wherein none of the joining means on the implement comprise the sole definition of any part of the top of the implement.
Another object is to provide a tool assembly comprising an implement interface having front and rear joining means, and an implement joined to the interface and adapted to accommodate rotation of the implement with respect to the interface.
Another object is to accommodate such rotation in the tool assembly about an axis of rotation, which axis extends from the implement toward the front of the interface.
Still another object is to provide a method of coupling, to a vehicle having a three-point hitch, an implement having joining means not adapted to be coupled directly to the three-point hitch, by interposing an appropriate implement interface between the implement and the three-point hitch.
Another object is to provide a method comprising coupling an implement interface to a three-point hitch and coupling an implement to the implement interface.
A further object is to provide a method to release an implement from securement to an implement interface, to rotate the implement about 180 degrees with respect to the interface, and to re-secure the implement to the interface, all while maintaining at least partial engagement between the implement and the interface.